Molding-machine.



E. P. PITFIELD.

MOLDING MACHINE. APFLIQATION FILED MAR. 3, I913.

1.268,?68. Patented June 4,1918.

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E. P. FlTFlELD.

MOLDING MACHINE. APPLICATION FILED MAR. 3, 1913..

1,268,768.. Patelztsefi it 1 918.

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I the pressure head in operative; position.

E'MLEN I. PTTFIELD, OF CAMBRIDGE, MASSACHUSETTS.

MoLDINe-MAoHrNE.

Specification of Letters Patent. Patented June &, 1918.

i Application filed March 3, 1913 Serial No. 751,719.

To all whom it mdyconcern: i

Be it known that I, EMLEN P. PITFIELD, a citizen of the United States, and resident of Cambridge, county of Middlesex, State of Massachusetts, have invented an Improvement in Molding-Machines of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

The present invention relates to molding machines for use in various founders molding operations for producing various types and sizes-of castings. One of the prime objects of the invention is to produce a molding machine, adapted tojoltthe sand in the flask, to compact the same about the pattern, the flask beingpreferably adapted to swing from an upright to an over turned position after having its sand contents securely clamped and held therein around the pattern. A further object of the invention is to provide a unitary mechanism adapted to effect a preliminary jolting. action to compact the sand about. the pattern, and thereafter by a continuing movement to hold the sand reliably packed in place, while the flask is turned to inverted position. A still further object is to provide an improved mountingof pressure head whereby it can be swung into and out of operative position with great facility; To these ends the invention'm its preferred embodiment consists in a flask carrier or table'mounted on horizontal trunnions, and adapted to be moved by a plunger or operated by fluid or otherwise, first with a jolting action to compact the sand, and thereafter with a longer movement to press the flasks against the pressure head, which pressure head is preferably mounted on four parallel links, whereby it is adapted to swing to operative position, over the flasks or laterally therefrom, at will. The above and other objects and features of the invention will be better understood from the following detailed description taken in connection With the accompanying drawings and will be thereafter pointed out in the appended: claims.

Referring to the drawings.

Figure 1 is aside elevation of a machine constructed in accordance with my invention, showing the pressure head laterally displaced. 1

Fig. 2 is a similar side elevation, showing Fig. 3 is a front elevation of the machine.

Fig. 4 is a side elevation, showing the flask inverted. i i

Fig. 5 is a side elevation, showing the flask table in an intermediate or vertical position. 5

Fig. 6 is an enlarged central, vertical section, showing a fluid pressure lifting means for the flask table. l r y Fig. 7 is a vertical section, showing a modified form of flask table lifting means,

wherein magnetic devices are employed.

Fig. 8 diagrammatic vlew, showing commutator controlling means of the form shown in Fig. 7. v

A suitable base support 1 is formed with spaced apart uprights 2, 2 having bearings 3, 3 for horizontal trunnions, 4, 4, which support the flask table and its controlling, and cooperating mechanism. As shown the trunnions 4, 4 have an intermediate ofl'set connecting portion 5, from which depends a cylinder 6, which may be integral therewith. This cylinder has fitted to slide therein a plunger 7 to an outer end flange 8 of which is bolted the flask table or carrier 9. For cooperation with the flask table 9, I mount thereover a pressure head 10, this. being carried by two pairs of parallel arms 11, 12, which are pivotally engaged at 13, with the extremities of rods 14, at each side of the pressure head. Thearms 11, 12 are pivoted at their lowerportions as at 15 to swinging bars 16 journaled on trunnions 4, and one of the arms of each pair 11, 12 is extended below its pivot point15, some little distance as seen at 17 and has pivotally secured thereto as at 18 the end of; a piston rod 19, which works in a eylinder20, pivotally carried as at 21, on a bracket 22, fixed to the flask table. The piston 19, and hence the pressure head 10 are controlled in. suitable manner as by a rotary valve 23, adapted to direct a pressure fluid to each end of the cylinder for moving the pressure head over the flask table, and laterally therefrom as later more fully explained.

In Fig. 6 I show in detail, fluid operative mechanism for lifting the flask table 9. In this embodiment the plunger 7 is hollowed out as seen at 24, with an inwardly extend ing flange 25 at its bottom fitting around its top, fitting the hollowed out bore 24 of the plunger 7, the piston stem 26 beingshown as upstanding from and rigid w1th,

the bottom of cylinder 6. Fluid ressure is admitted above the piston head 2 and be neath the bottom flange of plunger 7 through a duct 28 for lifting the flask table, and a duct 29 extends up through the piston stem26 intoathe hollowed interior of the .plunger 7, to return the plunger when required, the fluid pressure admission for this purpose belng controlled by the hand valve 30.

Inac'cordancewlth my invention means carried by the trunnion supports is providedffor efl'ecting the preliminary jolting of the flask holding table, and thereafter moving the table with a continuousmovement, through a relatively long range, and impa'rtingholding pressure to hold the sand pressed around the patterns in the flasks as thetable is inverted. To this end Ishow thepressure fluiclinlet through duct 28, as controlledby a slide valve 31 to whichis fixed an operating 'stem 32 having spaced apart tappets 33 at its upper end. These tappets 33 are alternately engaged to move the slide valve back and forth, by a fork 34, formed at the end of a bracket 35, fixed adjustably by a clamp pin and slot connection 36 underneath the table 9. The bracket 'is equipped with an outwardly extending handle '37, whereby as its clamp pin is released, it may be pulled out so as to disengage the fork 34: from operative relation with the'tappets 33. It may now be understoodthat as'the flask boxes are set in place on the flask table, and filled with sand around the pattern portions, the table is given a succession of jolting movements, being lifted a 'short distance by the fluid pressureadinitted withthe valve 31 in the positionshown in Fig. 6, the fluid pressure then passing through inlet conduit 38, from an inlet connection 39 through one of the trunnions; thetable after thus moving up a short distance, shifting the slide valve 31 to shut oflthe inlet pressure, and open the exhaustthrough passage 40, as is usual in slide valveactions, permitting the table to drop quickly with a jolt, and then be at once again raised as the slide valve is again shifted... This 'jolting operation thus automatically continues until the sand properlyf compacted aboutthe pattern, when the flaskbox covers being set in place, and 'the pressure head 10 positioned over the flash table, the fork34'is withdrawn, whereuponthe slide valve31 remains in its lowered position and the fluid pressure is supplied continuously,lifting theflask table up until theflasks on it'are pressed against pressure head 10, as seen at a,"b in Fig. 3. It is to be'understood thatthe proportions of parts including the downwardly offset portion 5 of the trunnion support: and the relatively massive cylinder 6',"are such that while the flask table is in lowered position, the center of gravity ister of gravity is thus elevated substantially above trunnions 4, so that the table tends to turn over on the trunnions to inverted position, this turning tendency may be controlled by suitably placednotches {ll on the trunnions, with which a lock bolt 4L2, onthe trunnion bearing support is adapted to co operateltohold the flask therein in uprlght position, or in inverted position, or in an iiite'rmediate position'as seen in Fig. 5, with the flask holding table vertical. The fluid pressuresupply for actuating pistons 19 to move the pressure head to and from operative position, is as shown through 'a conduit 43, which receives the fluid from conduit pipe 38, with a hand valve control as at 44.

In operation the'fi'ask portions a, b are placed on the flask table when it is in up rigl1t,horiZontal position, as seen in Fig. 1, and as normally held by the action of gravity, the piston 19 being then thrust outward, andthe pressurehead 10 being supported on the obliquely vdisposed parallel links 11, 12 at one side of the table. As the flasks are filled with sand around the pattern portions, the table is set jolting by the'admission of fluid pressure through the conduit 38 the fork 34'being then pushed inward for engagement with the tappets 33 and thus the sand inthe flasks is compacted and filled in closely around the pattern contour. When the flasksare filled with sand thus compacted, and the covers placed thereon, the valves 23 are turned to admit pressure for drawing in the pistons 19to an intermediate position, where the pressure head is directly over the flasks. Thereupon the fork 34 is withdrawn out of operative relation to the tappets 33, thus permitting the fluid pressure to act continuously lifting the table 9 up until the tops of the flasks are pressed strongly against the pressure head 10. It is tobeobserved that the special fluid pressurearrangement shown in Fig. 6, is particularly adapted forexerting great pressure within a small area, for the reason that the pressure fluid"exerts its lifting action liothabove the top of piston 27, and above the bottomfof the'cylinder G. The weight of the'flask table-9, and the flasks thereon, at their now greaterdistance from the trun nion axis, is sufiicient to overbalance the cylinder 6 and parts below the trunnion axis so that the table now tends to turn over'toinvertedposition assoon as released by 'the lock bolt 42. As it is thustu'rned over to "inverted position for the drawing of the pattern, it is to be observed that the flasks areheld securely pressed betweentable 9, and "the pressure head 10, by the rest on the pressure head. The flask portions may now be conveniently assembled to form the complete mold, and to bring them in better position for this, and also for removal from the pressure head on to a suitable conveyer, I preferably swing the trunnion support around a further quarter revolution,

to the position seen in Fig. 5,at the same time admitting pressure to the cylinders 20 to force the pistons therein completely inward, the result being that the pressure head with the mold therein, occupiesa forwardly projected, horizontalposition with the flask table vertical and at one side as clearly shown in said figure. Thus the mold may be readily transferred to a truck or other carrier.

In Figs. 7 and 8, I show aform of the invention as to the flask table lifting mechanism, wherein the lifting of the table is accomplished by magnetic action instead of fluid pressure. In thiscase the cylinder 6 has a plunger 7 fitted therein with the flask table 9, bolted thereto in like manner, as in the just described form. The cylinder 6 in this case is annularly recessed around the plunger as seen at 45 to receive a series, shown as seven of solenoid windings, 46, these windings being energized so that adja cent ones are of opposite polarity. At the lower end ofplunger 7 is formed an annular recess, in which is fitted a solenoid winding47, which is always thus closely adjacent, and in operative relation to one of the windings 46. Suitable means is provided for successively reversing the direction of current through the solenoid 47 ,so as to reverse its polarity, and for this purpose, 1 preferably provide a rotary drum 48, journaled in a suitable bracket support fixed to the cylinderas seen at 49, this drum bearing a series of contacts from a source of current 50. To effect the preliminary jolting of the flask table, in this case I provide a pair of brushes 51 pivotally mounted. at 52,. to be swung at will against the drum 48, and being then in position for engaging pairs of contacts which are connected toreverse the polarity of solenoid 47, as soon as it rises above the lowest winding 46' to the next winding 46". For this purpose the drum 48 is turned with a shade-roller, motion by means of a chain and sprocket connection 54 from the table 9, the drum having a usual spring device (not shown) for tending to turn it to wind up this chain. Thus the table is caused to reciprocate. within short limits, by the successive reversal of polarity in the solenoid 47 causing alternate attractions and repulsions in. the solenoids 46', 46" respectively. It is requisite for the proper jolting action, that the plunger or table should strike against a fixed abutment with some force, and to permit this and prevent premature lifting of the table by too early reversal of current, I preferably provide a dash-pot device or like retarding device 55 in the chain and sprocket connection 54, whereby the drum 48 will not turn back to reverse the current until the plunger has struck the fixed abutment at the bottom of the cylinder.

To provide for the extended lift of the table afterthe jolting is completed, I provide means whereby the solenoids 46 are successively energized from the bottom up with opposite polarity, and the solenoid 47 reversed as to its direction of polarity at the proper intervals, to be moved up continuously by alternate attractions and re pulsions of the solenoids 46; for this purpose brushes 51 are swung out of operative,

position, and a series of brushes 56 also pivotally mounted is swung into operative position to engage a series of coi'itacts 57, these brushes 56 andthe contacts 57 being connected in a manner known in the art to effect the described action. I consider the construction of fluid operating mechanism particularly shown in Fig. 6 to be a valuable and important feature of the invention since thereby a relatively large pressure area is provided within compact limits, the effective pressure area being represented by that of the face of piston head 27 plus that of the bottom face of plunger 24. This enables the requisite heavy pressure to be obtained within the relatively small limits that are practically valuable and the apparatus is thus better adapted for the combined preliminary jolting and subsequent fin al lifting and inverting. action. described. I am aware that the various features of the invention can be embodied in numerous other specific forms without departing from the spirit thereofand I therefore do, not desire to be limited to the present or any particular embodiment but refer to the appended claims rather than to the foregoing description to indicate the scopeof the invention.

I-Iaving described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Apparatus prising a flask holder, and means for holding and moving the same, said means having provision for jolting the holder, and having a trunnion mounting whereby the holder may be inverted, said trunnion mounting bearing said holder and the means for moving same complete, including such jolting provlslon.

2. Apparatus of the kmd described, comprisin a flask table mounted on trunnions adapting it to be inverted, and means alse of the kind described, com-.

carried complete by such trunnion mounting for imparting an automatic succession of.

jolts to the flask table for compacting the contents thereof.

3. Apparatus of the kind described, comprising a flask table having a mounting on trunnions permitting it to be inverted, such mounting being arranged to hold the table normally upright by gravity, and means carried complete by said trunnion mounting for imparting a succession of jolts to the table while it is in upright position for compacting the sand contents of flasks thereon.

4. Apparatus of the kind described, comprising a flask table having a trunnion mounting formed to hold it normally upright and horizontal by gravity, and means for imparting a succession of vertical jolts to the table and for lifting the table to over balance it whereby it tends to turn to in-' verted position at will, said means carried wholly by said trunnion mounting.

5. Apparatus of the kind described, comprising a holder for mold flasks mounted on trunnion bearings and arranged to remain normally upright and horizontal by gravity, and means for lifting the table on its trunnion mounting to facilitate inversion thereof, there being also provision for olting the table before such lifting, said means and jolting provision beingcarried Wholly by said trunnion mounting.

6. Apparatus of the kind described, com prising a flask holder having a trunnion mounting, and mechanism for lifting the same to facilitate inversion, said mechanism having provision to effect a preliminary jolting of the holder for compacting the sand contents of the flask thereon and being carried wholly by said trunnion mounting.

7. Apparatus of the kind described, comprising a flask holder and having a pressure head cooperative therewith both mounted complete on a trunnion bearing, means for holding the flasks pressed against said pressure head as they are inverted and means for eflecting a preliminary jolting of the flask holder, also carried complete by said trunnion bearing.

8. Apparatus of the kind described, comprising a flask holder resting on a plunger,

a trunnion mounting formed with a cylinder in which said plunger is fitted and a slide valve device for controlling said plunger having cooperative provision. for effecting a preliminary jolting action and thereafter a final lifting action at will upon the flask holder.

9. Apparatus ofthe kind described, comprising a trunnion mounting formed with a cylinder, a plunger fitted in said cylinder and bearing a flask table, said parts being formed to hold the flask table normally horizontal andupright, a slide valve device for controlling said plunger, andmeans carried by the table adapted to operate said valve device to effect a preliminary jolting of the table but beingdisengageable to. permit a subsequent lifting ofthe table for the purpose stated.

10. Apparatus of the kind described,comprising a flask table having a trunnion mounting with provision for lifting the table at will, and a pressure head cooperative with. said table for holding the flasks compressed, said pressure head being mounted on parallel links pivoted to permit the pressure head to swing laterally.

11. Apparatus ofthe kind described, comprising a flask table having a journal mounting and biased to remain normally upright and horizontal, means for lifting said table, and a pressure. head mounted on spaced apart parallel links adapting it to swing in-andfout from over the table, there being fluid operated means connected to said links for controlling such in-and-out movement.

12. Apparatus of the kind described, comprising a flask table having a journal mounting and equipped with provision for a lifting action on'said mounting, such pro vision consisting of a cylinder carried by said mounting, a hollow plunger supporting the table fittedin said cylinder, and a piston head fitted within said plunger and fixed to a stem carried by said mounting, there being provision for admitting fluid pressure beneath said plunger, and above said piston head to act on an'upper portion of said plunger. v

y In testimony whereof, I have signed my name to this specification, in the presence of;

two subscribing witnesses.

EMLEN P. PITEIELD.

Witnesses:

Lomsn A. JORDAN, C. L. Roenns' Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, I). G. 

